• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.7-11
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• 2003

Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, an analysis on the ship's collision causes is very important to prepare countermeasures which will ensure the safe navigation. And the analysis confirmed that ship's collision is occurred most frequently and the cause is closely related with human factor. The main purpose of this study is to build a model of human factors in ship's collision cause using SD(System Dynamics} approach and to measure a effect which is risk control countermeasures of ship's collision. To achieve this aim, the structure analysis on the causes of ship's collision using FSM are performed, and the structure was changed by quantitative, qualitative factors and their feedback loops in casual map. This model was performed over 20 years(1993-2012) in a standard simulation model and 8 policy simulation models.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.405-411
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• 2016

This paper presented the theory related to a two dimensional linear cross-sectional analysis, recovery relationship and a one-dimensional nonlinear beam analysis for composite beam with initial twist and high aspect ratio. Using VABS including related theory, preceding research data of the composite wing structure has been modeled and compared. Cross-sectional analysis was performed and 1-D beam was modeled at cutting point including all the details of real geometry and material. The 3-D strain distribution and margin of safety at recovery point was calculated based on the global behavior of the 1-D beam analysis and visualize numerical results.

• The Korean Journal of Pain
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• v.27 no.2
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• pp.162-167
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• 2014

Background: Although a physician may be the nearest to the radiation source during C-arm fluoroscope-guided interventions, the radiographer is also near the fluoroscope. We prospectively investigated the radiation exposure of radiographers relative to their location. Methods: The effective dose (ED) was measured with a digital dosimeter on the radiographers' left chest and the side of the table. We observed the location of the radiographers in each procedure related to the mobile support structure of the fluoroscope (Groups A, M and P). Data about age, height, weight, sex, exposure time, radiation absorbed dose (RAD), and the ED at the radiographer's chest and the side of the table was collected. Results: There were 51 cases for Group A, 116 cases for Group M and 144 cases for Group P. No significant differences were noted in the demographic data such as age, height, weight, and male to female ratio, and exposure time, RAD and ED at the side of the table. Group P had the lowest ED ($0.5{\pm}0.8{\mu}Sv$) of all the groups (Group A, $1.6{\pm}2.3{\mu}Sv$; Group M, $1.3{\pm}1.9{\mu}Sv$; P < 0.001). The ED ratio (ED on the radiographer's chest/ED at the side of the table) of Group A was the highest, and the ED radio of Group P was the lowest of all the groups (Group A, $12.2{\pm}21.5%$; Group M, $5.7{\pm}6.5%$; Group P, $2.5{\pm}6.7%$; P < 0.001). Conclusions: Radiographers can easily reduce their radiation exposure by changing their position. Two steps behind the mobile support structure can effectively decrease the exposure of radiographers by about 80%.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.20-29
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• 2021

This study aims to explore the issue of drones and crime in newspaper articles. BIG KINDS, an online news archive of the Korea Press Foundation, collected 1,213 newspaper articles that met the terms of "drone" and "crime" in 11 central and 28 regional comprehensive newspapers between January 1, 1990 and May 1, 2021. Among them, we perform keyword frequency, centrality analysis, network structure construction, CONCOR analysis, and density matrix analysis on 117 key keywords. According to the analysis, the main issues were classified into eight, and the report analysis on drones and crimes in newspaper articles showed that the government's policy-making and social problems on protecting people's privacy, preventing illegal filming, securing navigation safety, social security and resolution. This study attempts to expand the field of humanities and social studies related to drones and crime, and specifically suggests the current status and counterplan against drone-related crimes as policy implications and media implications.

• Korean small business review
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• v.43 no.4
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• pp.155-172
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• 2021

This research means that it analyzed the conflict structure of key stakeholders in the operation and management of the Regulation Free Zone. The analysis results are as follows. First, for the safety review related to the amendment of the law, the process of presenting a preliminary review opinion is additionally required. Second, institutional improvement is needed for the complicated preliminary preparation stage in the management system issue. Third, there is the issue of whether to provide an incentive structure to the local innovation ecosystem or to leave it to the autonomy of the participating companies and guarantee the choice in the post-management issue. In the future, this research suggests a method to systematically prepare a micro-policy demand identification process through continuous monitoring using the Q method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.141-152
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• 2022

As interest increases related to the development of eco-friendly energy, the offshore wind turbine market is growing at an increasing rate every year. In line with this, the demand for an installation vessel with large scaled capacity is also increasing rapidly. The wind turbine installation vessel (WTIV) is a fixed penetration of the spudcan in the sea-bed to install the wind turbine. At this time, a review of the spudcan is an important issue regarding structural safety in the entire structure system. In the study, we analyzed the current procedure suggested by classification of societies and new procedures reflect the new loading scenarios based on reasonable operating conditions; which is also verified through FE-analysis. The current procedure shows that the maximum stress is less than the allowable criteria because it does not consider the effect of the sea-bed slope, the leg bending moment, and the spudcan shape. However, results of some load conditions as defined by the new procedure confirm that it is necessary to reinforce the structure to required levels under actual pre-load conditions. Therefore, the new procedure considers additional actual operating conditions and the possible problems were verified through detailed FE-analysis.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.69-80
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• 2022

The proportion of buildings over 30 years old in Korea has increased, from 29.0% in 2005 to 37.8% in 2019. These old buildings were built during a time in which there was a lack of building-related safety standards in areas such as fire safety performance. Worse, during their years of use, many such old buildings have had illegal changes and extensions made, making them more vulnerable in terms of safety. Fire safety investigations are being conducted to prevent large-scale disasters in multi-use buildings, but no investigation has been conducted at the regional district level, where small-scale old buildings are concentrated. Therefore, to identify fire risk factors in the old building district where old buildings are concentrated, the composition characteristics of the buildings were first analyzed. To examine the spatial characteristics of old building districts in order to derive fire risk factors, the results of this analysis based on the structure, use, roof type, and year of approval for use are as follows. It was found through our analysis that as of the date of approval for the use of the building, the main structure of the building has the greatest impact.

• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.29-41
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• 2007

An assesment technique for the quantitative evaluation of tunnel safety during tunnel excavation was newly proposed in this study using displacement measurements. First of all, field measurement guidelines used at tunnel construction sites in Korea and other countries were investigated. It was found out that the criteria of the guidelines were not clear and varied depending on the construction sites. The practical use of field measurement data for the evaluation of tunnel safety was very limited due to uncertainties of the guidelines related to the interpretation of measured data during the excavation. Critical strain concept is introduced in this study for the assesment of tunnel safety during the tunnel excavation. Moreover, the characteristics of tunnel displacements caused by the tunnel excavation were investigated in detail in order to investigate the practical application of the critical strain concept. The total tunnel displacements can be subdivided into three parts: displacements occurring ahead of tunnel face, displacements occurring prior to measurements, and displacements occurring after the installation of instruments. The characteristic of each portion of displacements is analysed in this study. Finally, a general method on the use of the displacement measurement data for the critical strain concept was suggested in the concrete manner, considering the field measurement practice in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.230-237
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• 2023

Due to the COVID-19 pandemic and climate change, shortages of essential commodities and resources continue to occur globally. To address this problem, trade volume demand suddenly increased, driving up the freight rate of container ships sharply. The size of container vessels progressively increased from 1,500 TEU (twenty-foot equivalent unit) in the 1960s to 24,400 TEU in 2021. As the improvement of container loading capacity is closely related to the enlargement of the lashing bridge structure, it is necessary to design a structure effective for good container securing and safe under the various external loads that occur during voyage. Major classification societies have recently issued structural-analysis-based guidelines to evaluate the structural safety of lashing bridges, but their acceptance criteria and evaluation methods are different, causing confusion among engineers during design. In this study, the strength change characteristics are summarized by variations in the main variables (modeling range, opening consideration, mesh size) likely to affect the results. Based on this result, the authors propose a reasonable structural-analysis-based evaluation that is expected to serve as a reference in the next revision of classification standards.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.345-354
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• 2009

The review of statements and coastal development characteristics in South Korea were diagnosed by the consultation on the coastal area utilization in Korea. The occupation and the use of public water were dominated by installation of coastal structure and seawater supply and drainage whereas the reclamation areas were predominantly utilized for developing industrial complex, harbor, fishing port and road. The occupation and the use were dominant in western coast, but reclamation was dominant in southern coast of Korea. The number of utilization cases was particularly greater in Jeonnam, Gyeongnam, and Gyeonggi Province including Incheon. The number of the statements reviews increased by more than 200 cases in 2008 compared with 2007, and most of them were the simple statements. The statements related to ocean disposal of dredged sediment, reclamation, dredging sediment, seawater supply and drainage, and marine sand mining were submitted for review. Coastal utilization was especially active in the regions of seawater quality criteria I and II. In particular, special management sea areas designated under the relevant marine regulations were utilized mostly by reclamation for developing harbor, fishing port and coastal structure. Development activities in national parks comprised primarily structure installation and coastal maintenance. In the fisheries resources protection areas, 40% of the total cases accounted for coastal maintenance, 31% for structure installation, and 16% for seawater supply and drainage. In addition, alternative plans for the improvement in policies and system of marine environmental impact assessment were suggested to enhance the function and confidence of the consultation on the coastal area utilization in Korea.